from The American Heritage® Dictionary of the English Language, 5th Edition.

  • intransitive verb To change or make different; modify.
  • intransitive verb To adjust (a garment) for a better fit.
  • intransitive verb To castrate or spay (an animal, such as a cat or a dog).
  • intransitive verb To change or become different.

from The Century Dictionary.

  • To make some change in; make different in some particular; cause to vary in some degree, without an entire change.
  • To change entirely or materially; convert into another form or state: as, to alter a cloak into a coat; to alter an opinion.
  • To castrate, emasculate, or spay, as an animal.
  • To exchange.
  • To agitate: as, ”altered and moved inwardly,” Milton, Areopagitica, p. 1.
  • To become different in some respect; vary; change.

from the GNU version of the Collaborative International Dictionary of English.

  • intransitive verb To become, in some respects, different; to vary; to change
  • transitive verb To make otherwise; to change in some respect, either partially or wholly; to vary; to modify.
  • transitive verb obsolete To agitate; to affect mentally.
  • transitive verb colloq. To geld.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • verb transitive To change the form or structure of.
  • verb intransitive To become different.
  • verb transitive To tailor clothes to make them fit.
  • verb transitive To castrate, neuter or spay (a dog or other animal).

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • verb cause to change; make different; cause a transformation
  • verb remove the ovaries of
  • verb become different in some particular way, without permanently losing one's or its former characteristics or essence
  • verb insert words into texts, often falsifying it thereby
  • verb make an alteration to


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English alteren, from Old French alterer, from Medieval Latin alterāre, from Latin alter, other; see al- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Old French alterer (French altérer), from Medieval Latin alterare ("to make other"), from Latin alter ("the other"), from al- (seen in alius ("other"), alienus ("of another"), etc.; see alias, alien, etc.) + compar. suffix -ter.


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